In recent years, with development of the ocean, oil digging rig or steel structures such as oil storage purge and sea plant ships, piers of long bridges constructed in the sea, and steel structures in water of sea air ports have been increasingly constructed. These steel structures are substantially impossible to transmit to another place for the maintenance or corrosion repairing thereof, and such operations must be carried out under bad conditions such as in the sea or at a location where water is splashed. For this reason, it has been desired to develop a corrosion repairing method which can be easily carried out on or in the sea.
Japanese Patent Application (OPI) No. 137034/79, for example, discloses a coating method which can form a coating having excellent corrosion resistance on portions in water or splash zones of underwater structures in a simple and easy manner as on the ground (the term "OPI" as used herein refers to a "published unexamined Japanese patent application").
Conventional compositions for use in such underwater coating include a composition comprising an epoxy resin as a base resin, polyamide or polyamine as a curing agent and a filler as described in Japanese Patent Application (OPI) No. 67400/76. However, these conventional compositions have disadvantages that underwater coating properties are poor and coatings are quite easily lost by waves during hardening because of their poor adhesion force. Even if the coatings harden, the hardened coatings have poor adhesion properties and therefore anticorrosion over a long period of time cannot be expected.